Fuel cell module for vehicles

ABSTRACT

A fuel cell module for a vehicle, which accommodates a stacked-cell body which is provided with electric output terminals for taking electric power from stacked power generating cells in a metallic casing which has an insulation layer on its inner surface, is disposed in a vehicle front room such that the stacked direction of the power generating cells is a longitudinal direction of the vehicle and the electric output terminals face the front of the vehicle. An insulating cover made of insulating rubber which is thicker than an insulation layer of a cover is disposed on the exterior surface of the electric output terminals to prevent short circuiting of the electric output terminals.

TECHNICAL FIELD

The present invention relates to a structure of a fuel dell module forvehicles.

BACKGROUND ART

In recent years, automobiles using fuel cells as a source of driveenergy have attracted attention as one possible measure for addressingenvironmental problems. In conjunction with this, there has been anoticeable effort to develop technology for installing fuel cells in thefront section of automobiles. For example, Japanese Patent No. 3767423describes a fuel cell-powered automobile in which a fuel cell isinstalled in the front end of the vehicle, the power generating cells ofthe fuel cell are stacked in the width direction of the vehicle, and acircuit breaker and an electric output terminal for receiving electricpower from the fuel cell are arranged on a side face of the vehicle. Inthe described configuration, the fuel cell is housed in a casing forprotection.

Because the position of the electric output terminal for receivingelectric power from the fuel cell moves due to heat expansion of thefuel cell, there has also been proposed a fuel cell output terminalhoused in a bellows as described in Japanese Patent Publication JP-A5-74473, and an output cable for receiving electric power from the fuelcell covered with an insulator as described in Japanese PatentPublication JP-A 2002-208314

Meanwhile, technology for producing high voltage fuel cells having alarge capacity has progressed, and high-performance vehicles in whichsuch cells are installed are now being studied. However, as the voltageand capacity of fuel cells increase, there dimensions such as width andlength become large, possibly to the extent that it may not be possibleto stack the power generating cells in the width direction, in whichcase the fuel cell cannot be installed in the width direction of thevehicle. In such a case, it might become necessary to stack the powergenerating cells in the longitudinal direction of the vehicle and toinstall the fuel cell in the longitudinal direction of the vehicle.

In a case where the fuel cell is installed in the longitudinal directionwithin the front section of the vehicle, a fuel pipe and the likeconnecting to the fuel cell are arranged on the rear side in a fuel cellinstalling space of the vehicle in view of safety. In such aconfiguration, the electric output terminal from the power generatingcells would likely be arranged on the front end of the power generatingcells, in the vehicle front section, the side opposite to the connectionports of the fuel pipe and the like.

When the electric output terminal is arranged towards the front of thevehicle, the casing in which the fuel cell is housed may be deformed ifthe vehicle body adjacent to the fuel cell is deformed as a result ofthe vehicle colliding with an object. Although an insulation coating isapplied to the inner surface of the casing for the fuel cell, theinsulation coating can become broken because of the contact between thedeformed casing and the electric output terminal, in which case theelectric output terminal and the casing may become electricallyconnected, possibly resulting in a short circuiting of the electricalsystem.

When the fuel cell is installed on the vehicle front side as describedabove, the power generating cells are stacked along the longitudinaldirection of the vehicle, and a side face of the stacked-cell bodybecomes a side face of the vehicle. With such a configuration, the sideface of the casing in which the fuel cell is housed might becomedeformed due to the deformation of the vehicle side face in the event ofa collision impacting the side of the vehicle. When the side face of thecasing is deformed, the deformed casing comes into contact with the sideface of the stacked-cell body, resulting in a possibility that a shortcircuit occurs between the individual stacked power generating cellsthrough the metallic casing. Even when the inner surface of the metalliccasing is insulation-coated, contact of the metallic casing with thepower generating cells may still damage the insulation coating, with theresult, again, that a short circuit as described above may occur.

If a short circuit occurs between the electric output terminal of thefuel cell and the vehicle or between the power generating cells, therewere problems that an abnormal electric potential is generated in thepower generating cells, for example, sintering of a catalyst, oxidationof supported carbon, or the like is generated, resulting indeterioration of the catalyst.

DISCLOSURE OF THE INVENTION

The present invention may be configured as a fuel cell module for avehicle of the invention is a fuel cell module for a vehicle including astacked-cell body which is provided with electric output terminals fortaking electric power from stacked power generating cells, and ametallic casing which has an insulation layer on its inner surface andaccommodates the stacked-cell body, wherein an insulator which isthicker than the insulation layer is disposed between the insulationlayer and the electric output terminals.

The present invention further provides a fuel cell module for a vehicleof the invention is a fuel cell module for a vehicle, including astacked-cell body which is provided with a positive electric outputterminal having a voltage higher than a ground potential and a negativeelectric output terminal having a voltage lower than the groundpotential, and a metallic casing which has an insulation layer on itsinner surface, accommodates the stacked-cell body and has the samepotential as the ground potential, wherein an insulator thicker than theinsulation layer is disposed between the insulation layer and theindividual electric output terminals.

In the fuel cell module for a vehicle of the invention, the stacked-cellbody is preferably disposed at the front end of the vehicle, with thepower generating cells stacked in the longitudinal direction of thevehicle and the electric output terminals located on the vehicle frontside; the insulator is preferably made of insulating rubber or aninsulating resin; the insulator is preferably an insulating cover forcovering the electric output terminals; the insulator is preferably aninsulating plate which is disposed on the inner surface of the casing;and the insulating plate is preferably fixed to a tightening member forthe stacked-cell body.

The present invention may further be configured as a fuel cell modulefor a vehicle of the invention is a fuel cell module for a vehicle,including a stacked-cell body having power generating cells stacked, anda metallic casing for housing the stacked-cell body, wherein aninsulator is disposed between the metallic casing and a surface of thestacked-cell body opposite a side face of the vehicle. In the fuel cellmodule for a vehicle of the invention, an insulator is preferablydisposed between the metallic casing and individual surfaces, which areopposed to individual side faces of the vehicle, of the individualstacked-cell bodies which accommodate a plurality of the stacked powergenerating cell bodies and are disposed on both side faces of thevehicle; a thin insulating sheet thinner than the insulator ispreferably disposed between a plurality of the stacked power generatingcell bodies; the metallic casing has preferably an insulation layer onits inner surface, and the insulator is thicker than the insulationlayer; and the insulating sheet is preferably thicker than theinsulation layer.

Application of the present invention makes it possible to prevent shortcircuiting of the electric output terminals of the fuel cell module fora vehicle or between the power generating cells of the fuel cell modulefor the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view showing a fuel cell module according toa first embodiment of the present invention installed in a vehicle.

FIG. 2 is an explanatory view showing a connected state of powergenerating cells of the fuel cell module according to the firstembodiment of the present invention.

FIG. 3 is a schematic elevation view of a fuel cell module according tothe first embodiment of the present invention mounted in a vehicle.

FIG. 4 is a partial sectional view of a fuel cell module includingelectric output terminals according to the first embodiment of thepresent invention.

FIG. 5A is a perspective view of an insulating cover according to thefirst embodiment of the present invention in an open state.

FIG. 5B is a perspective view showing an assembled state of aninsulating cover according to the first embodiment of present theinvention.

FIG. 6A is an explanatory view showing a section of the insulating coverattached to the electric output terminals of the fuel cell moduleaccording to the first embodiment of the present invention.

FIG. 6B is an explanatory view showing an insulating cover attached tothe electric output terminals of the fuel cell module according to thefirst embodiment of the present invention.

FIG. 7 is a schematic elevation view showing an example of deformationof a vehicle and a fuel cell module when the front of a vehicle on whicha fuel cell according to present invention is involved in a collisionwith an object.

FIG. 8 is a schematic sectional view of a fuel cell module according toanother embodiment of the invention.

FIG. 9 is a schematic showing a sectional view of a fuel cell moduleaccording to still another embodiment of the invention.

FIG. 10 is a schematic plan view showing a vehicle-mounted fuel cellmodule according to still another embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the invention will be described with referenceto the figures.

FIG. 1 is a schematic plan view of the front section of an automobile(vehicle front section) in which is installed a fuel cell moduleaccording to the first embodiment of the present invention. In FIG. 1, afuel cell module 11 is installed in a room 10 at the vehicle frontsection. The fuel cell module 11 has a casing 12 in which a stacked-cellbody 15 is housed. The casing 12 has a casing body 12 a and a cover 14and houses the stacked-cell body 15 airtight. For the convenience ofexplanation, the cover 14 and insulating covers attached to individualelectric output terminals 21, 23 are omitted from the figure so that theconfiguration of the stacked-cell body 15, cables, and the likecontained are visible.

The stacked-cell body 15 has a first cell stack 17 and a second cellstack 18 which are stacked bodies of power generating cells 16 which areplate-like unit cells, electrode plates 21 a, 23 a which are stacked atone end of the individual cell stacks 17, 18, and end plates 19, 20which are arranged on both sides of the individual electrode plates 21a, 23 a. The individual cell stacks 17, 18 which are arranged inparallel are configured to include the same number of power generatingcells 16 and to generate the same voltage. The stacked direction of eachof the first cell stack 17 and the second cell stack 18 is alongitudinal direction of the vehicle, and the individual cell stacks17, 18 and the individual electrode plates 21 a, 23 a are compressed inthe stacked direction by the metallic end plates 19, 20 which arearranged at their front and rear ends and have a relatively largethickness (for example, a thickness of about 15 mm).

As shown in FIG. 2, in the first cell stack 17 and the second cell stack18 the power generating cells 16 are stacked with polarities directed toopposite directions from each other. The first cell stack 17 haspositive terminals directed to the vehicle front and negative terminalsdirected to the vehicle rear shown in FIG. 1, and the second cell stack18 has negative terminals directed to the vehicle front and positiveterminals directed to the vehicle rear shown in FIG. 1. The ends of thefirst cell stack 17 and the second cell stack 18 on the side of the endplate 20 are electrically connected to each other. Thus, the cell stacks17, 18 compose a series-connected unit cell body of one power generatingcell 16 and provides a desired high voltage. The electrically connectedends on the side of the end plate 20 are also connected to the vehiclebody, and their connection point is a ground electric potential.

Therefore, the electric output terminal 21 of the electrode plate 21 astacked at the end on the side of the end plate 19 of the first cellstack 17 and the second cell stack 18 becomes a positive electric outputterminal having a voltage higher than the ground electric potential, andthe electric output terminal 23 of the electrode plate 23 a stacked onthe second cell stack 18 becomes a negative electric output terminalhaving a voltage lower than the ground electric potential. The metalliccasing 12 mounted in the vehicle body becomes the ground electricpotential.

While the end plates 19, 20 are fixed to the casing 12, the dimensionsof the cell stacks 17, 18 may change in the stacked direction due tothermal expansion, contraction, or the like resulting from temperaturechanges. Accordingly, stacked disc springs (not shown) are assembledbetween the end plate 19 and the electrode plate 21 a and between theend plate 19 and the electrode plate 23 a to configure such that thepower generating cells 16 which are unit cells configuring the cellstacks 17, 18 are always press-contacted mutually by a proper force.

Within the casing 12 are sheathed cables 31, 33 for bringing electricpower from the stacked-cell body 15, a relay 25 which cuts off a harness35 and an electric circuit, the electric circuit, a distributor (notshown), and the like. The relay 25 and the electric output terminals 21,23 which are a positive terminal and a negative terminal areelectrically connected through the flexible sheathed cables 31, 33. Thesheathed cables 31, 33 are fixed to the positive and negative electricoutput terminals 21, 23 and the terminals of the relay 25 by a bolt 26and a nut 28.

A service plug 27 is attached to a position on the side and rear sideface of the casing 12, while the relay 25 and the service plug 27 areelectrically connected by the sheathed harness 35 for each positive andnegative terminal. Additionally, a power output cable 37 is extendedfrom the service plug 27 to the exterior of the casing 12, and theharness 35 and the power output cable 37 are electrically connected bythe service plug 27.

With the configuration as described, electric power generated by thefuel cell module 11 is output from the power output cable 37 via therelay 25 and the service plug 27, and the output can be cut off by therelay 25 and the service plug 27. The relay 25 controls electrical flowbetween the terminals to which the sheathed cables 31, 33 are connectedand the terminal connected to the harness 35 for the positive andnegative terminals, according to an externally-supplied control signal.For example, the relay 25 is normally kept ON when the vehicle istraveling or the like, and it is possible to output from the fuel cellmodule 11. Meanwhile, the relay is switched OFF according to a controlsignal which is issued when a crash sensor (not shown) detects acollision or the like of the own vehicle, and the output from the fuelcell module 11 is cut off.

Meanwhile, the end plate 20 of the stacked-cell body 15 is provided witha fuel inlet pipe 41 and an exhaust gas discharge pipe 43. These pipesare arranged on the rear side under the vehicle front room 10 where thecasing 12 is disposed.

Additional components for operating the vehicle, such as a radiator 51or the like, are housed in the vehicle front room 10 in addition to thecasing 12 in which the stacked-cell body 15 is housed, and front wheels57 are fitted on both sides. The radiator 51 is disposed between thecasing 12 and a front grill 53 at the front of the room 10, andconfigured to be connected to a coolant path circulating within the fuelcell module 11, in order to enable cooling of the liquid coolantcirculating through the coolant path.

FIG. 3 is a schematic elevation view showing the fuel cell module 11installed in the vehicle front room 10. As shown in FIG. 3, the vehiclefront room 10 has a shape which protrudes beyond the vehicle front.Additionally, a vehicle interior 63 where a steering wheel 59 and thelike are installed and the area in the room 10 are separated by apartition wall 61.

The fuel cell module 11 is installed near the center of the room 10 andfixed to the vehicle body such that the power generating cells 16 arestacked in the longitudinal direction of the vehicle. The stacked-cellbody 15 is housed in the casing body 12 a. The casing 12 is madeairtight by fixing the cover 14 to the top of the casing body 12 a. Thecasing body 12 a and the cover 14 have an insulation layer 13 on theirinner surfaces. The individual electrode plates 21 a, 23 a of thepositive terminal and the negative terminal are stacked at the front ofthe stacked-cell body 15, and the individual electrode plates 21 a, 23 aare provided with the individual electric output terminals 21, 23 whichare projections projecting toward the vehicle top. Further, the cover 14is formed to have a bulged section in the area towards the front whichcovers the individual electric output terminals 21, 23, so as to providea necessary clearance for these individual electric output terminals 21,23.

As shown in FIG. 4, the individual electrode plates 21 a, 23 a of thepositive terminal and the negative terminal are configured to beinsulated from each other by a middle partition, and the individualelectric output terminals 21, 23 of the positive terminal and thenegative terminal are arranged to project. The cover 14 of the casing 12bulges upward from the connected surface to provide a clearance for theindividual electric output terminals 21, 23 as shown in the figure, andthe insulation layer 13 is disposed on the inner surface. The insulationlayer 13 may be provided using an insulation coating or the like. Theindividual electric output terminals 21, 23 are square plates formed ofa conductive material such as copper or the like and have a hole formedin their center. Meanwhile, the sheathed cables 31, 33 which takeelectric power from the individual electric output terminals 21, 23 areflexible cables, and connecting terminals 29, 30 for connection with theindividual electric output terminals 21, 23 are attached to one ends ofthe individual sheathed cables 31, 33. The connecting terminals are madeof a metal plate having its leading end bent into an L shape and a holefor fixing the center. The bolt 26 is inserted through each of the holesformed in the centers of the individual electric output terminals 21, 23and each of the holes formed in the connecting terminals 29, 30 andfixed by tightening the nut 28. Thus, the connecting terminals 29, 30 ofthe sheathed cables 31, 33 are attached and fixed to the individualelectric output terminals 21, 23.

Insulating covers 22, 24 are attached as insulators to cover theexternal surfaces of the individual electric output terminals 21, 23 andthe connecting terminals 29, 30 fixed to the individual electric outputterminals 21, 23. The insulating covers 22, 24 are preferably formed ofa material such as rubber having sufficient thermal conductivity. Asshown in FIG. 5A, the individual insulating covers 22, 24 are configuredof, for example, nut sides 22 a, 24 a and bolt sides 22 b, 24 b of theindividual electric output terminals 21, 23. One end each of theinsulating covers is integrally formed and the other end is openable, sothat they are easily attached to the individual electric outputterminals 21, 23. The insulating covers 22, 24 are configured to haveinner surfaces with recessed portions to conform with the individualshapes of the electric output terminals 21, 23; the connecting terminals29, 30; the bolt 26 and the nut 28 so as to cover these components, andthe exterior surface externally protruded according to the recessedportions so the insulator will have a substantially uniform thickness.Tightening bands 32, 34 are attached on the side of an opening. Thetightening bands 32, 34 have a hole in one end and a hook attached tothe other end. As shown in FIG. 5B, after the insulating covers 22, 24are attached to the individual electric output terminals 21, 23 and theconnecting terminals 29, 30, the holes of the tightening bands 32, 34are caught by the hooks to firmly fix the individual insulating covers22, 24 to the individual electric output terminals 21, 23.

FIG. 6A and FIG. 6B show sectional views of the insulating covers 22, 24which are attached to the outside surfaces of the individual electricoutput terminals 21, 23 and the connecting terminals 29, 30. As shown inFIG. 6A, when the individual insulating covers 22, 24 are fixed to theindividual electric output terminals 21, 23 by the pressure of thetightening bands 32, 34; the inner surfaces of the individual insulatingcovers 22, 24 are firmly attached to the individual surfaces of theindividual electric output terminals 21, 23, the connecting terminals29, 30, the bolt 26 and the nut 28 by virtue of the elasticity of thematerial rubber. Therefore, heat from the individual electric outputterminals 21, 23 which are also heat generators is transmitted to theindividual insulating covers 22, 24 and readily radiated from theoutside surfaces. Thus, the individual electric output terminals 21, 23can be prevented from having an increase in temperature. In addition,because the insulating covers 22, 24 have a substantially equalthickness with respect to the individual electric output terminals 21,23 and the connecting terminals 29, 30, heat radiated from theindividual surfaces is not dissipated, heat from the individual electricoutput terminals 21, 23 can be radiated evenly from the entirecircumference, and temperature variations can be eliminated.

As shown in FIG. 6A and FIG. 6B, because the insulating covers 22, 24have a thickness greater than that of other insulation coating or thelike, when they receive an outside impact, they can absorb the impactand reduce an occurrence of a damage to the insulating covers 22, 24 byvirtue of their thickness, so that the insulated states of theindividual electric output terminals 21, 23 can be maintained.

Next, deformation of the room 10 and the fuel cell module 11 and theretention of the insulated states of the individual electric outputterminals 21, 23 in the event that the front of a fuel cell vehicleinstalled with the fuel cell module 11 configured as described abovecomes into collision with another object will be described.

As shown in FIG. 7, when the front of the fuel cell vehicle collideswith another object, a crash sensor (not shown) detects the collisionand turns off the relay 25 to cut off the output from the fuel cellmodule 11. A bumper 55 which is mounted on the front of the vehicle ispushed toward the vehicle rear as a result of the front-end collision.In addition, the room 10 including the front grill 53 of the vehicle isshortened due to compression deformation and the radiator 51 between thefront grill 53 and the fuel cell module 11 is displaced rearwards andpushed against the casing body 12 a of the fuel cell module 11 and thecover 14. Because the casing body 12 a and the cover 14 are formed of,for example, a metal such as an aluminum alloy or the like, their frontparts are crushed by plastic deformation. At this time, the cover 14 isdeformed to be compressed in the longitudinal direction of the vehicleand the swelled portion on the top of the cover 14 is also deformeddownward, towards the individual electric output terminals 21, 23. Thus,the deformation causes the inner surface of the cover 14 to come intocontact with the insulating covers 22, 24 which are attached to theexteriors of the individual electric output terminals 21, 23. Asdescribed above, the electric output terminal 21 is a positive electricoutput terminal having a voltage higher than ground electric potential,and the electric output terminal 23 is a negative electric outputterminal having a voltage lower than the ground electric potential.Because the cover 14 and the casing body 12 a are made of metal andprovide ground potential, such deformation will likely cause damage tothe insulation between the metallic cover 14 and one or both of themetallic electric output terminals 21, 23, such that the cover 14 willcome into direct contact with one or both the electric output terminals21, 23, in which event a short circuit will result due to the voltagedifference between the ground electric potential and the positivevoltage or between the ground electric potential and the negativevoltage. Even if the electric output of the fuel cell module 11 is cutoff by the relay 25, the individual electrode plates 21 a, 23 a of thefuel cell module 11 are in states of high positive voltage and negativevoltage, so that, when a short circuit as described above occurs, anabnormal electric potential is generated in the power generating cells16, and a catalyst is deteriorated by, for example, sintering of thecatalyst, oxidation of supported carbon, or the like. In addition, ifthe insulation between both the electric output terminals 21, 23 and thecover 14 which is a conductor is damaged, a short circuit may resultbetween the electric output terminals 21, 23 through the cover 14.Because the resulting voltage difference is twice that of the differencebetween the cover 14 and one of the electric output terminals 21, 23,and the result damage to the catalyst is significantly greater.

However, because in the present embodiment the individual electricoutput terminals 21, 23 o have thick rubber insulating covers 22, 24,contact of the cover 14 to the exterior surfaces of the individualelectric output terminals 21, 23 is far less likely to damage theinsulation layer 13 which is formed of a soft insulation coating, andthe metallic cover 14 and the individual electric output terminals 21,23 are therefore unlikely to contact each other. Therefore, shortcircuiting between the cover 14 and the individual electric outputterminals 21, 23 or between the electric output terminals 21 and 23 canbe effectively prevented, so that an advantage is achieved in that thedeterioration of the catalyst as a result of abnormal electricpotentials in the power generating cells 16, for example, sintering ofthe catalyst, oxidation of supported carbon, or the like, can beprevented.

Even when the insulation layer 13 on the inner surface of the cover 14is formed of an insulation coating or the like and cannot respond to alarge plastic deformation of the metallic cover 14 and the coatedsurface is separated from the metallic surface to expose the metallicsurface toward the inner surface of the cover 14, an advantage is stillachieved in that the insulating covers 22, 24 attached to the individualelectric output terminals 21, 23 are able to maintain an insulated stateto effectively prevent the electric output terminals from shortcircuiting.

A second embodiment will next be described with reference to FIG. 8.Corresponding components which function in the same manner as those ofthe previous embodiment are denoted by the same reference numerals asthose used in the previous embodiment, and their detailed descriptionswill not be repeated. The fuel cell module 11 of this embodiment has aresin insulating plate 45 attached to the inner surface of the cover 14of the casing 12, which houses the stacked-cell body 15, with resininsulating bolts 47. It is sufficient that the insulating plate 45 beassembled between the electric output terminals 21, 23 and theinsulation layer 13 on the inner surface of the cover 14, and its widthmay be configured to be equal to the total width of the fuel cell module11 or equal to just the electric output terminal portion. And, as theresin insulating bolts 47 for attachment, it is configured to enable toprevent a short circuit between the cover 14 and the electric outputterminals 21, 23 or between the electric output terminals 21 and 23 viathe cover 14, even if the insulating bolts 47 come into contact with theelectric output terminals 21, 23.

The resin insulating plate 45 has a thickness greater than that of theinsulation layer 13 which is disposed on the inner surface of the cover14, and is configured to prevent, by virtue of its thickness, shortcircuiting between the individual electric output terminals 21, 23 andthe metallic portions of the cover 14, even in the even of a collisiondeforming the bulge in the cover 14.

Referring to FIG. 9, another embodiment will be described. Correspondingcomponents which function in the same manner as those of either of theprevious embodiments are denoted by the same reference numerals as thoseused in the previous embodiment, and their detailed descriptions willnot be repeated. In this embodiment, a resin insulating plate 46 isassembled to a tightening member for tightening the end plate 19 of thestacked-cell body 15 housed in the casing 12 or the power generatingcells 16, such as a tension plate, which is not shown. In thisembodiment, the insulating plate 46 is fixed to the end plate 19 withthe insulating bolts 48. The insulating plate 46 is assembled betweenthe electric output terminals 21, 23 and the insulation layer 13 formedon the inner surface of the cover 14, and formed to be thicker than theinsulation layer 13 so that, even if the bulge of the cover 14 isdeformed towards the electric output terminals 21, 23 as a result of acollision or the like, the metallic portion of the cover 14 will notcome into contact with the electric output terminals 21, 23, and a shortcircuit will not occur. The insulating plate 46 may be configured to beattached to the entire face in the width direction of the fuel cellmodule 11, or to just the electric output terminals 21, 23. Similar asin the previous embodiments, this embodiment also produces anadvantageous effect that short circuiting between the cover 14 and theindividual electric output terminals 21, 23 and between the electricoutput terminals 21 and 23 can be effectively prevented.

Although in the examples described with reference to FIG. 8 and FIG. 9,insulating covers 22, 24 are not provided for the individual electricoutput terminals 21, 23, it is also preferable that the insulatingcovers 22, 24 are attached in addition to the resin insulating plates45, 46 similar to the embodiment shown in FIG. 1 to FIG. 6.

Referring to FIG. 10, a still further embodiment will be describedbelow. Corresponding components which function in the same manner asthose of the previous embodiments are denoted by the same referencenumerals as those used in the previous embodiment, and their detaileddescriptions will not be repeated. In this embodiment, the first andsecond cell stacks 17, 18 configuring the stacked-cell body 15 arehoused in the casing 12 of the fuel cell module 11. As shown in FIG. 10,an insulating plate 49 is disposed between the casing 12 and a left sideface of the cell stack 17, which faces towards one side of the vehicle.Also as shown in FIG. 10, another insulating plate 49 is also disposedbetween the casing 12 and a right side face of the cell stack 18, whichfaces towards another side of the vehicle, and an insulating sheet 50 isdisposed between the first and second cell stacks 17 and 18. Theinsulating plate 49 may be formed of a rubber plate or a resin plate.The insulating sheet may be formed of a rubber plate or a resin platewhich is thinner than the insulating plate 49. The insulating plate 49and the insulating sheet 50 may be attached to the casing 12 withinsulating bolts or the like or may be configured to attach to theindividual cell stacks 17, 18.

The present invention may be configured such that the insulation layeris provided by insulation coating on the inner surface of the casing 12,or such that the insulating plate 49 is thicker than the insulationlayer.

By employing a configuration as described above, there is produced aneffect that, in the event of a side collision, occurrence shortcircuiting between the power generating cells via the casing due to thedeformation of the casing can be effectively prevented. Further, byproviding a thick insulator on the side face which is easily deformed toenhance the insulating property of the side face, there is produced aneffect that the insulator can be reduced.

1. A fuel cell module for a vehicle including a stacked-cell body whichis provided with electric output terminals for taking electric powerfrom stacked power generating cells, and a metallic casing which has aninsulation layer on its inner surface and accommodates the stacked-cellbody, wherein: an insulator which is made of insulating rubber or aninsulating resin and thicker than the insulation layer is disposedbetween the insulation layer and the electric output terminals.
 2. Thefuel cell module for a vehicle according to claim 1, wherein thestacked-cell body is disposed in the vehicle front room, the powergenerating cells are stacked in the longitudinal direction of thevehicle, and the electric output terminals are oriented facing towardsthe front of the vehicle.
 3. (canceled)
 4. The fuel cell module for avehicle according to claim 2, wherein the insulator is an insulatingcover which covers the electric output terminals.
 5. The fuel cellmodule for a vehicle according to claim 2, wherein the insulator is aninsulating plate which is disposed on the inner surface of the casing.6. The fuel cell module for a vehicle according to claim 5, wherein theinsulating plate is fixed to a tightening member for the stacked-cellbody.
 7. A fuel cell module for a vehicle, including: a stacked-cellbody which is provided with a positive electric output terminal having avoltage higher than a ground electric potential and a negative electricoutput terminal having a voltage lower than the ground potential, and ametallic casing which has an insulation layer on its inner surface,accommodates the stacked-cell body and has the same potential as theground potential, wherein: an insulator which is made of insulatingrubber or an insulating resin and thicker than the insulation layer isdisposed between the insulation layer and the individual electric outputterminals.
 8. The fuel cell module for a vehicle according to claim 7,wherein the stacked-cell body is disposed in the vehicle front room, thepower generating cells are stacked in the longitudinal direction of thevehicle, and the electric output terminals are oriented facing towardsthe front of the vehicle front.
 9. (canceled)
 10. The fuel cell modulefor a vehicle according to claim 8, wherein the insulator is aninsulating cover for covering the electric output terminals.
 11. Thefuel cell module for a vehicle according to claim 8, wherein theinsulator is an insulating plate which is disposed on the inner surfaceof the casing.
 12. The fuel cell module for a vehicle according to claim11, wherein the insulating plate is fixed to a tightening member for thestacked-cell body.
 13. A fuel cell module for a vehicle, including: astacked-cell body having power generating cells stacked, and a metalliccasing for housing the stacked-cell body, wherein: an insulator made ofinsulating rubber or an insulating resin is disposed between themetallic casing and the surface of the stacked-cell body opposite thatof the vehicle body.
 14. The fuel cell module for a vehicle according toclaim 13, wherein an insulator is disposed between the metallic casingand individual surfaces, which are opposed to individual side faces ofthe vehicle, of the individual stacked-cell bodies which accommodate aplurality of the stacked power generating cell bodies and are disposedon both side faces of the vehicle.
 15. The fuel cell module for avehicle according to claim 14, wherein a thin insulating sheet thinnerthan the insulator is disposed between plurality of the stacked powergenerating cell bodies.
 16. The fuel cell module for a vehicle accordingto claim 13, wherein the metallic casing has an insulation layer on itsinner surface, and the insulator is thicker than the insulation layer.17. The fuel cell module for a vehicle according to claim 14, whereinthe metallic casing has an insulation layer on its inner surface, andthe insulator is thicker than the insulation layer.
 18. The fuel cellmodule for a vehicle according to claim 15, wherein the metallic casinghas an insulation layer on its inner surface, the insulator is thickerthan the insulation layer, and the insulating sheet is thicker than theinsulation layer.